Integrated circuit laser devices are manufactured on wafers which are two inches in diameter and about 12-20 mils thick. After initial manufacture, the wafers are thinned to about 3.5-4.5 mils and separated into smaller units, called sections, with four sections being derived from a single wafer. The sections are trimmed in one dimension, which we will call length, to be about 0.4 inches long. They are also scored across their widths to define 20-30 subdivisions, called bars, which are about 12 mils wide and about 0.4 inches long.
During subsequent processing, the sections are divided into bars by breaking or cleaving them along the scribed lines, to form facets along their elongated sides. After the cleaving process, the cleaved laser bars are transported side-by-side on a plastic film sheet, with their lengths extending laterally of the sheet. Before the bars are cleaved into individual chips, the individual chips on each bar are tested. This requires removal of the bars from the sheet and their placement into a test fixture. After testing and other operations, the bars are replaced on the sheet and subjected to further cleaving in order to separate the individual laser devices.
The laser bars and the individual chips are small, delicate structures, which are not to be handled by hand. Accordingly, a handling probe, called a "collet" has typically been used to handle integrated circuit structures. A collet typically has a handling head which is shaped to conform to the integrated circuit structure and which is connected to a vacuum source, which permits the handling head to retain the structure. For example, collets for laser bars are long and narrow, owing to the shape of the bar. Furthermore, the handling head must be formed with a long narrow slot to accommodate the application of the vacuum to the long, narrow laser bar. Typically, this slot is 12 mils by 320 mils. Such diverse dimensions can be achieved reliably only with electrical discharge machining (EDM) and the use of tungsten carbide as the collet material. However, tungsten carbide is a relatively abrasive material, and it often happens that, in handling the bar, the collet will brush against its surface. This can damage the relatively soft materials on the surface of the chip and, particularly, the gold contacts and conductive portions.
In accordance with the present invention, the conforming collet utilized for integrated circuit structures is replaced by a plurality of individual collects of the type utilized for integrated circuits. These are typically made of polymide, which is substantially softer than tungsten carbide which is used for larger collects of odd shape. In a preferred embodiment, the elongated collect usually used with respect to laser bars is replaced by two individual collects of the type described, which contact the laser bars only near their ends.